<html>
<head>
<style>
  div.wrapper { 
    width:  100px;
    height: 30px;
  }
  div.a, div.b {
    height: 20px;
    display: inline-block;
  }
  div.a {
    width: 20px;
    background: blue;
  }
  div.b { 
    width: 80px; 
    background: green;
  }
</style>
</head>
<body>
  <div class="wrapper">
    <div class="a"></div> <div class="b"></div>
  </div>
</body>
</html>
